One of my rental properties had this mess at the back. I didn't even know there was a shed back there until after I bought it!
It had ugly roofing shingles for siding, which were half-worn off. Here is the progression.
The inside was full of junk, and a lot of really smelly junk - used cat litter, dead birds, etc. I emptied it out (or rather, paid others to empty it out!), and fixed up the outside. Trimmed up the locust tree, cleaned up the yard, and REALLY did a number on the house a year ago.
But the shed was this week.